Steam-hammer.



' PATENTED MAY 2s, 1905.

' A. L. BICI-IER. STEAM HAMMER.

k.@.PPLIOATION FILED ooT.1'z. 1904.

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ATToR N'EY UNTTED STATES Patented May 23, 1905.

ALBERT L. EIOHER, O F ALLIANCE, OHIO.

STEAM-HAMMER.

` SPECIFICATION forming part 4of Letters Patent No. 7 90,566, dated May23,1905.

Application filed October 12, 1904. Serial No. 228,113l

To all whom t may concern:

Be it known that I, ALBERT L. EIOHER, a citizen of the United States,residing at Alliance, in the county of Stark and State of Ohio, have.invented a new and useful Improvement1l in Steam-Hammers, of which thefollowing 4is a specification.

The invention relates to steam-hammers; and the general object of theimprovement is to make a connection between the piston-rod and thehammer which will permit the hammer to give a substantially free blowand at the same time save the rod from the shocks and strains caused bythe blow and rebound of the hammer and the consequent crystallizationand breaking of the rod.

The present practice is to attach the pistonrod by tapering its lowerend and forcing it into a similarly-tapered axial aperture in thehammer. This aperture must necessarily extend entirely through thehammer, so the end of the rod can be driven out from below in event itbreaks off above, which circumstance quite frequently occurs. Such arigid connection not only subjects the piston-rodto all the shocks andstrains of the blow and rebound of"the hammer, but makes it verydiflicult for the engineeigunless he be a more skilful one than' isusually obtainable, to manipulate the valves of the steam-cylinder forproperly placing the blow of the hammer both as to time and quality,which saine largely depends on the relative time the steam is reversedwith reference to the delivery of the blow of the hammer. Thesedifficulties are overcome by the mechanism, construction, andarrangement illustrated in the accompanying drawings, in which- Figure 1is a front elevation of an ordinary steam-hammer with some parts'insection, showing the general features of the invention, and Fig. 2 anenlarged sectional View showing the connection of the piston-rod in thehammer more in detail.

Similar numerals refer to similar parts throughout the drawings.

The hammer 1 operates vertically between the guides 2 ofthe frame 3 andhas.V the detachable die 4 o'n its lower end. The an vil 5 is locatedbeneath thehammer and has the die-block 6 attached thereon, and thedieblock has the detachable die 7 on its upper side, which is arrangedto receive the blow of the hammer-die.v

The cylinder 8 is-mounted on end directly above the hammer and isprovided with the usual piston 9 with the attached rod 10 and the upperand lower ports 11 and 12, with the usual valves, levers, andconnections for operating and controlling the same. The upper head 13 ofthe cylinder is provided with the c ylindric dome 111, forming thecushion-chamber 15, in which the cushion-pistonl is adapted to operate..The short piston-post 17 eX- tends downward from the center of thecushion-piston through the aperture 18 in the cylinder-head, in whichaperture the post is adapted to operate. The cushion-piston normallyrests on the cylinder-head, and in this relation the post extends ashort distance into the cylinder, so that the upper side of theenginepiston strikes the end of the post and is cushioned by the air orsteam in the chamber 15 and is thereby prevented from striking thecylinder-head.

The elongated. axial cylindric cavity 19 is provided in the hammer andextends from the upper end to a point near the lower end, but

with the partition 20 between the cavity and the die-seat, so the sameis not weakened. The piston-rod 10 is somewhat less in diameter than thehammer-cavity, into which it is inserted, and near the lower end of therod are mounted one or more packing-rings 21, which completely close thecavity below them. The retaining-collar 22 is removably attached in theYupper`end of the hammer-cavity and servesr as a stop against which thepackingrings will strike to prevent `the piston-rod from being withdrawnfrom the hammer-cavity. This collar is put in place after the rod Vhasbeen inserted in the cavity, and its inner diameter is made larger thanthe diameter of the rod, thus leaving the annular interval 23 betweenthem. The retaining-collar is not designed to act as a stop on thepacking-ring in the active operationof the hammer, but only when it isheld for some time in an elevated position and the leakage of air pastthe packing-ring permits it to drop downward. From this construction andarrangement it will be noted that there is no contact or connectionbetween the piston-rod and the hammer, excepting only indirectly by thepacking-rings. The lower end of the piston-rod is preferably formed withthe bell-shaped concavity 24, with the rim 25 thereof extending near tobut not quite touching the wall of the hammer-cavity, thus leaving onlythe constricted interval 26 around the rim, and between the rim and thepacking is preferably provided the considerable annular recess 27, whichserves as a reservoir to save the packing from excessive air-pressure orsuction.

The bottom 28 of the hammer-cavity is preferably formed reverselysimilar to the lower end of the piston-rod, and the end of the rod isnormally located at a short interval from the bottom of the cavity, thusforming the vacuum-chamber 29 in the lower end of the cavity. Vhile theair in this chamber may occasionally be compressed, and thus act as acushion, in the proper operation of the hammer it is more frequentlyexpanded to form a quasi-vacuum, and for this reason I prefer to call ita vacuum-chamber.

In the operation of the steam-hammer constructed and connected asdescribed it is designed to reverse the steam an instantthat is, a briefinterval of time-before the hammer delivers its blow, with the eect thatthe piston-rod is stopped and may be started upward when the hammer-diestrikes the anvildie or the intervening blank or forging, so that duringthis instant or interval the hammer moves downward independent of thepiston-rod, which is either stationary or moving upward, and theincreased separation of the end of the piston-rod from the bottom of thehammer-cavity creates a quasi-vacuum in the intervening chamber. Whilethe suction caused by the quasivacuum does not act quickly or powerfullyenough to materially affect the force of the hammers stroke, it doesdevelop energy enough to catch the hammer immediately on its rebound andto promptly carry it upward for another stroke, and the blow of thehammer thus freely given is more sudden, sharp, and snappy than ispossible to be given by a hammer having a fixed or rigid connection withthe piston-rod. In fact, it is almost impossible with such a rigidconnection to surely deliver the most effective quality of a blow withthe hammer, because if the steam is reversed too soon the hammer isarrested in its downward movement and started upward before the strokeis fully made, while if the steam is not reversed soon enough the strokeis heavy and too long sustained for the best results. On the other hand,with the free-rod vacuum-chamber connection there is quite a littleleeway as to the time the steam must be reversed,which is covered by theelasticity of the connection. If, perchance, the steam is not reversedbefore the hammer strikes, the pistonrod is cushioned against the shockby compressing the air in the vacuum-chamber; but this situation neednot arise if the parts are so proportioned that the engine -pistonreaches the lower end of the stroke before the hammer makes its blow.Furthermore, by providing the annular interval 23 between the pistonrodand the retaining-collar the cylindric cavity remains open at the upperend, and there is no closed pocket in which air is caught and compressedand the free downward movement of the hammer thereby retarded when theblow of the hammer is delivered. In other words, there is nothing torestrain the free downward movement of the hammer when the piston hasbeen reversed` excepting only the friction of the packing-ring in thecylindric cavity and the resistance of the air against expansion orrareiication in the closed cavity below the ring, which resistance ismanifestly more sensitive and delicate than that of air incon'ipression, and especially so if it is accompanied by suchcompressed-air resistance, which would be the case if the cylindriccavity were closed at the upper end as well as at the lower end. Bythese means there is thus obtained substantially the same quality orcharacter of a blow by a steamhammer that is delivered by a drop-hammer,with the additional advantage that the pistonrod on which the hammer issuspended is entirely free from any contact or connection with thehammer, excepting only the sliding contact of the packing-ring, whichsaves the rod from all longitudinal shocks, and this same contact, inconnection with the entire freedom of the rod above, permits the hammerto oscillate sidewise in event the hammer strikes an uneven surface andsaves the rod from all lateral strains, and as it is such lateralstrains as well as longitudinal shocks that causes the piston tocrystallize and break this danger and damage is avoided bytheconstruction described herein. When thepistonrod acts to compress theair below it, the action is so quick that the bell-shaped lower endcatches the air like a parachute and there is no opportunity for muchair to escape th rough the constricted interval around the rim into theannular recess thereabove, and this recess acts as a supplementalcushion to keep the full force of the compression from the packing, and,reversely, when a vacuum is formed in the chamber below the end of thepiston-rod the action is so quick there is no opportunity for much ofthe air in the annular recess above the rim to pass down through theconstricted interval around it, so that the recess acts as asupplemental vacuum-chamber to save the packing from the full force ofthe suction.

Vhile a small amount of leakage past the packing-rings does notmaterially aifect the operation of thehammer, as described, because IOO`1 of the quickness of its stroke, yet if the hammer is suspended on thepiston-rod for an eX- tended period such leakage will permit the hammerto gradually drop down along the rod until the retaining-collar isstopped against the upper packing-ring. For this reason I prefer toprovide the axial port 30 in the piston-rod with the lateral branch 30a,opening at a convenient point above the hammer, and to provide asuitable check-valve 3l to permit the air to eXhaust from thevacuum-cavity, but to stop any air from entering'therein. By this meansthe hammer can be readjusted to its proper place on the piston-rod bymerely lowering it to a support on the anvil, when the rod can lbepushed into its normal position by expelling the surplus air from thevacuumchamber.

The means for providing a cushion for the steam-piston head at the upperend of its stroke illustrated and described,Y but not yclaimed herein,will be made the subject of another application for Letters Patent.

What I claim herein as my invention, and desire to secure by LettersPatent, is

l. In a steam-hammer, the combination of a hammer having a cylindriccavity therein, a piston-rod in the cavity, and a packing-ring on therod near its lower end and closing the cavity therebelow, the cavitybeing open at its upper end.

2. In a steam-hammer, the combination of a hammer having a cylindriccavity therein, a free piston-rod in the cavity, and a packingring onthe rod near its lower end and closingthe cavity therebelow, the cavitybeing open at its upper end- 3. In a steam-hammer, the combination of ahammer having a cylindric cavity therein, a piston-rod in the cavity, apacking-ring on the rod near its lower end and closing the cavitytherebelow, the cavity being open at its upper end, and aretaining-collar in the cavity above the packing-ring loosely encirclingthe pistonrod.

4. In a steam-hammer, the combination of a hammer having a cylindriccavity therein, a piston-rod in the cavity having a bell-shaped lowerend with a rim forming a constricted interval between the wall of thecavity and the rod, and a packing-ring on the rod near its lower end andclosing the cavity therebe- 5. In a steam-hammer, the combination of ahammer having a cylindric cavity therein, a pistoni-rod in the cavityhaving a rim on the lower end forming a constricted interval between thewall of the cavity and the'rod, with an annular recess above the rim anda packing-ring on the rod above the recess and closing the cavitytherebelow.

6. In asteam-hammer, the combination of a hammer having acylindriccavity therein, a piston-rod in the cavity, a packing-ring onthe rod near its lower end and closing the cavity therebelow, the cavitybeing open at its upper end, and means forV exhausting air from thecavity'when the rod is thrust inward.

ln testimony'whereof I have hereunto signed my name to thisspecification in the presence of two subscribing witnesses.

ALBERT L. EioHER.

Witnesses: Y

MINNIE F. ANTHONY, HARRY FREASE.

